Thanks for your inquiry. I believe the name of the third ship may be KENNETH A. J. MACKENZIE. That name comes pretty close to what you have. I can find no evidence of a ship with even a partial name of McKinsey.
The namesake of the ship, Kenneth A. J. MacKenzie (1797-1861), was a fur trader and merchant who organized the Columbia Fur Company in 1822. He was active in the upper Missouri River fur trade.
The U.S. Maritime Commission named most Liberty ships after deceased persons who had some significant role in the history of North America in general or of the U.S. in particular. (BOOKER T. WASHINGTON is a perfect example.) But with more than 2,700 Liberty ships to name, you can see that the Commission had to dig deep to find some worthy names.
(Anecdotally, during the Liberty shipbuilding program, some individuals contacted the Maritime Commission to volunteer the name of a relative or friend, or even their own name, as befitting having a ship carry that name. Informed that the namesake had to be deceased, they quickly withdrew their suggestions. In other cases, individuals contacted the Commission to thank or criticize the Commission for naming a ship after them. They were politely told that, sorry, the ship was actually named after someone of the same name who was, um, more famous than you -- and deceased.)
Incidentally, NIRA LUCKENBACH was not a Liberty ship. This was a ship built in 1919 as part of a World War I shipbuilding effort, although she was too late for that war. (The first Liberty ship was built in 1941.) She was a so-called Hog Islander ship, named after the Hog Island shipyard near Philadelphia where the ship was constructed. Hog Islanders were notable as being the first ships built in an assembly-line manner, with much of each ship being prefabricated. Many Hog Islanders were active in World War II -- at least 50 were lost in the war -- despite being near the end of their useful lives by then. The ship in question was built with a different original name, was renamed at least once, maybe twice, before becoming NIRA LUCKENBACH in 1940. She survived the war, was renamed once more, and was scrapped in 1953. (See http://shipbuildinghistory.com/shipyards/emergencylarge/aisc.htm and scroll to hull number 1492.) While so named, NIRA LUCKENBACH was owned by the Luckenbach Steamship Company, which gave most of its ships a Luckenbach last name. The ship apparently was named not for some member of the Luckenbach family as you might think but rather for Lady Nira, which was the name of a horse owned by the owner of the company.
And now you know a whole lot more than you expected.
Ron Carlson, Webmaster
Armed Guard / Merchant Marine website